<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>

</body>
<script>
    // 1-
    function fn(){

    }
    // 2
    const fn2 = function(){}
    // 3-:接收参数a,b,c返回a与b与c之和
    const fn3 = new Function("a","b","c","return a+b+c;");
    console.log(fn3(1,2,3));
</script>
</html>